This question could never give much of consensus when answered given that tastes differ so much.
But 2 raised points are similar to my view:
- they will search for somebody of what they think are similar to their own physical appeal.
- women are insecure regarding their body, more so than men, therefore, I see they choose less good bodies if they don't have a great body themselves, in order to feel a bit secure.
The above is overriden if the guy's body is very unimportant for the girl when choosing a mate.
The logical (IMO) option is athletic body within normal proportions. 10 years ago I was a lot into bodybuilding and power lifting so I was much heavier and with bigger muscles, I did it in spite of knowing that most people even dislikes this type of body, it was my desire.
But now, I am just athletic, visible muscles and lean body, but within normal proportions. Everybody who sees old pictures of me and current ones go: "wow, you look so much better now!"